Influence of foundation flexibility on the seismic response of low-to-mid-rise moment-resisting frame buildings

Document Type: Article


Department of Civil Engineering, University of Kashan, Kashan, P.O. Box 87317-51167, Iran


Recent studies have shown that the eff ects of Soil-Structure Interaction (SSI) may be detrimental to the seismic response of structure, and the neglect of SSI in analysis may lead to an un-conservative design. The objective of this study is to simulate the performance of multi-storey building-foundation systems through a Winklerbased approach. Four typical steel Moment-Resisting Frame (MRF) buildings on three soil types with shear wave velocities of less than 600 m/s subjected to actual ground motion records of varied hazard levels are modeled with and without SSI. It is observed that the performance level of models supported by
flexible foundation, particularly in an intense earthquake event, may alter signi cantly in comparison to fixed-based structures. Moreover, for MRFs on soft soil, the nonlinear foundation is found to have a signi cant
eff ect on the force and displacement demands. This indicates the necessity for consideration of
flexible foundation behavior in the modern design codes in order to accomplish a more economic yet safe structural design.


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